Flexible connecter



Feb. 26, 1929.

T. l. DUFFY FLEXIBLE CONNECTER Sheets-Sheet l Filed Dec. 13, 1924 Feb. 26, 1929.

T. l. DUFFY FLEXIBLE CONNECTER ls snets-sneet 2 Filed Dec. 13, 1924 @www0 Pat-exited' Feb. 26,1929.

,UNITED STATES PATENT OFFICE.

THOMASLI. DUFFY, OF CHICAGO, ILLINOIS, ASSIGNOR OF' ONE-HALF TO J'. COR'I WALKER, OF CHICAGO, ILLINOIS, AND ONE-HALF T ROBERT N. BURTON, 0F

CHICAGO, ILLINOIS.

FLEXIBLE CONNECTER. v

Application led December 13, 1924. Serial No. 755,593.

The purpose of this invention is to provide improved means for connecting two members having limited relative movement, particularly `when one or both of them is subject to rapid or violent vibration. The invention is illustrated as a connection between the frame and supporting spring of a road vehicle and when thus used its object is to dispense with the more usual metallic pivotal connections and the resent application'the connecting means is a so designed for controllingthe' fl'exure and vibration of the spring t-O some extent in that it tends to oppose excessive recoil of the spring after flexure and also to resist lateral twisting of the spring and side sway of the vehicle in travel. The invention involves certain features and elements adapted tov contribute to these objects as well as various details of construction shown in the Vseveral alternative forms hereinafter described and illustrated in the drawings while the novel features and combinations thereof are more particularly indicated by the claims.

In the drawings Figure-1 is a lside elevation of a Vehicle spring and a portion of the frame to which it is secured as viewed from the inner side 30 of the frame and therefore showing the axle on the spring in section.

Figure 2 is a detail view on a larger scale and partly in section showing the flexible connecter for the rear end of the spring of Figure 1. y

Figure 3 is a detail View similar to Figure 2 showing a modified form of attaching fittings for the connecter.

Figure 4 is a transverse section taken as indicated at line 4-`-4 on Figure 3.

Figure 5 is a vertical detail section showing a modified form of the connecter.

Figure 6 is a vertical detail section of an` other modification ofthe connecter, this form being particularly adapted to use at the'front end of the spring.

Figure7 is-another modified form'of front end connecter.

Figure 8 is a vertical detail section in a plane longitudinal with respect to the spring showing a further modification of the connecter.

Figure 9 is alsectional'view ofy the device shown in Figure 8 taken as indicated at .line 9 9 on Figure 8.

thus eliminate `the wear of such connections and the noise incident thereto. As shown in this invention in wh: 1h the yielding material l is reenforced by an embedded fabric.

Figure 11 is a section taken as indicated at line 11-11 on Figure 10.

Figure 12 isa side elevation of the vehicle front spring and a art of the frame using flexible connecters of) a modified form.

Figure 13 is a side elevation with a portion broken'away showing a rear spring and a corresponding part of the frame held together by flexible connecters, one of which is slmilar to that shown in Figure 12, while the other is a further modification.

lFigure 14 is a vertical detail section of the connecter shown at the front end of the spring in Figure 12, the plane of section being indicated at line 14%14 on Figure 15.

Figure 15 is a `frontrd'etail elevation of the connecter shown in Figure 14.

Figure 16 is a section similar to Figure 14 showing a modified form of the device.

Figure 17 is a section similar to Figure 16 showing another modification.

Figure 18 is a section similar to Figure 14 but showing the connecter used at the rear end of the spring of Figure 12.

This application represent-s a further dei velopment of the invention shown and claimed in my pending application Serial No. 703,016, filed March 3l, 1924. As applied to Vehicle springs its primary object is to eliminate the metal shackle of common usage and to produce a steadier spring action under better control than is ssible with the older pivotal connections. eferring first to Figure 1 a part of the vehicle frame is sh'own at Aand a spring, B, of the semi-elliptic type which may be understood as a front springpf the vehicle is attached to the frame mem er by my flexible conncct'ers, 1 and 2. A section of the front axle is indicated at C. Theconnecter, 2, is shown better in detail in Figuse 2 and comprises a. substantiall cylindrical block of rubber which is provi ed -with circumferential grooves, 3, adjacentv its upper, and lower ends for engagement with the 1n turned ribs, 4,-of diametrically divided capand to the longest leaf, B1, of the spring, B.

The solid'rubber of the block, 2, tends to absorb man spring be ore they reach the frame, A, at all.

The flexibility of the block, 2, permits itto engage the 25. to the frame andspring.

the block, 13, and the Ablocks are enclosed within the two-part me- The ends of the barrel are made with be distorted away from its axis to accommodate the longitudinal movement of the end of the spring, B, as the spring is flexed while at thesame time this distortion of the block, 2, involves enough resistance to spring flexure to act as a damping device for preventing excessive recoil.

As a modification of the split caps, 5, shown in Figure 2, I have presented in Figures andI 4, a pair of divided socket members, 9, having in-turned lips or flanges, 10, which block, 2, adjacent its ends and the members, 9, are formed with lugs, 11, to receive small clamping bolts, 12, for holding together the assembled halves of each cap. Attaching bolts 7 similar to those of Figure 2 are used for applying the assembled device In the form shown in Figure 5, the parts which are attached to the frame and spring respectively instead of embracing the rubber block are embedded'and locked within it. In this case` the block consists of three pieces comprising upper and lower sections, 13, and an intermediate section, 14. The attaching members are in the form of studs or posts, 16,

having heads, 17, which are embraced between block, 14. The rubber tallic casing or barrel whoseupper andA lower sections, 18 and 19, are screwed together at' 20, for longitudinally compressing the rubber to insure its firm engagement with the heads, 17, of the studs. The set screw, 21,'may be inserted to prevent unscrewing of the barrel after the parts have been once assembled. ample clearance openings, 22, through which the studs, 16, emerge for attachment to the frame and spring and within which they may tilt somewhat in accommodating spring'flexure.

In this form of the device it will be noted thatthe distortion of the rubber'due to. fiexure of the spring, B', will occur mainly in the' upper and lower sections, 13, surrounding the posts, 16, while the middle section, 14, acts to support the load and to absorb the'vibration.

In Figure 7 the rubber block, 1, is of suitable proportions for connecting the front end of the spring. to the frame and the details of thisdevice are similar to those of the connecter shown in Figure 2, except that the metallic caps or sockets, 23 are integral members intended to be placed in the mold` during the formation of the rubber block, 1, so that the block is actually molded into these caps, 23. The attaching bolts, 24, are likewise included in -the assembly when the vrubber is 1,7os,ves

of the miner vibrations/of theA locked by a cross pin,

stud, 16a, tothe surface of the connecters of this character is vspring leaf action may into tension vfor the' instant. It frequently molded. p `7 shows the same form of l frame termlnal, A2, as'Figure 1, this'being a cast member providing a downwardlyl facing fiat nad, A5, which is drilled and threaded to receive .one of the studs, 24., which may be 25, if desired.

Figure 6 shows a front end connection. similar in`theory to that of Figure 5 but because of the very` limited vdistortion reyquired at the front end of the spring I provide only a single stud, 16a, whose head, 16",

" is pocketd in `a block of rubber, 13a, andretained by a rubber block, 14a, above the head. The casing,15, is screwed directly toa thread formed on the' special pad, A4, at the front end of thev frame and at its lower end said casing, 15, provides a large clearance opening through which the rubber of the block, l

13a, extends downwardly surrounding the spring leaf, B1. vFigures 8 and 9` illustrate a modication of the same general type as Figure 5 but in this form the studs, 26, are madel with T-heads, 27, extending 'crosswise of the vehicle so as to allow the ydevice as avwhole to flex more freely in a lon itudinal plane of the vehicle and to' quite einitely oppose the lateral distortion which 'accompanies any twisting of the spring leaf. In this Way the w device tends to check` sidesway or shimmying of the vehicle on the road.' The T-shaped studs are assembled with sectional rubber.

blocks comprisin upper and lower parts, 28, anda metal bloc 29,`which are enclosed in a metallic barrel or casing, 30, as in Figure 5. In this form,`however, the rubber of the upper and lower'blocks, 28, extends through the large clearance openings in the ends of the barrel and completely encases the vstems of the studs, 26, up to the surface of the frame and spring respectively, so that these metal parts are not exposed to the weather and the rubber tends to exclude dirt or mois"- 'ture from them. p,

Although the principal duty of fiexible performed under load and therefore under compression, there are times when the devices are subjected to tensile strain; even the distortion due tonormal spring fiexure will cause bending of' the rubberblock producing tension at llO one side and frequently, the heavy recoil of throw the connecter happens, that the vehicle is designed so that the ,tractive effort is transmitted wholly or rackets imposes similar'strain shackles. Therefore, it is` h'the springs or that the optially vulcanized to cause the rubber to'flow into the fabric and form an integral tubular structure. This tube may then be cutS into short len ths of from one to two inches and the cut e ges of the fabric, 31, may besealed in by the addition of rubber at 32 and further vulcanizing to render the rubber homogeneous throughout. The annular block with its self contained re-enforcement is then punched to receive the fastening studs, 33, and the applied heads, 34, of the studs are accommodated in the central opening of the block. A central iiller of two parts of molded rubber, 35, is inserted between the heads,

34, of the studs and these two parts are secured by an axial bolt, 36. Between the frame fiange, A1, and the rubber connecter, and

likewise between the spring end, B1, and the rubber, I prefer to provide metallicpads,

37 and 38, respectively, which conform approximately to the curved out-line of the conne'ctor under load and thus distribute the load over a considerable area of the rubber. Such a 'connecter while adapted to be distorted suiciently to accommodate the spring under` all conditions, also serves as a strong tie member between the running gear and frame of the vehicle.

In Figures l2 to 18 I have shown several forms of connecters embodying the same principle as that of Figure 10. In Figure'12 the connecter, 40, shown at the front end of the spring is of triangular outline instead of approximately circular but may be made in' much the same manner as that of Figure 10.

However, I prefer in this instance to insert .vulcanizing so that all theA 'rubber of the device is thus welded into a unit with the metal parts permanently secured in place.. As applied to the front end of the frame I have shown one side of the triangle uppermost and lodged within the suitably formed cap pad,

A5, attached to the end of the framemember, A. The upper attaching stud is secured byan ornamental nut, 42, giving a finished appearance tothe device.- IVithin the connecter Aunitthe heads of the studs, 41, are laterally extended asf-shown at 43 and 44 in Figure 14, so -as tol present broad surfaces for engagement withv the Are--enforced triangle without danger of tearing-gwhen placed under strain. The core, 45, serves principally `for supporting the vehicle load as transmitted through these broad heads, 43 and 44, of the studs.

At the rear end of the lfront spring, B, shown in Figure 12 the connecter, 50, is of elongated or elliptical form but is made from tubing by the process'already described for the triangular device of Figure 14. This connecter is shown more in detail in Figure 18 in the position which it assumes before assembly in the vehicle.- Under normal load it is distorted rearwardly at'the lower end as indicated .in the full outline in Figure 12. The

dotted outline indicates approximately theV position and shape assumed by the connecter at the expected limit of recoil of the s ring, B, or at the probable limit of upper exure of the spring under load. Caps or pads, 52, are provided forseating the upper and lower ends of the connecter at the frame and spring and studs, 51, project from either end for securing the device tosaid parts. If-applied to the rear end of a rear spring as show n in Figure 13 the frame may have a specially formed pad, A", recessed to receive the rounded end of the connecter andthe ornamental nut, 54, may be used for finish. An interior plug, 55, is shown in Figure 18 serving the same purpose as the plug, 45, in the triangular connecter; in the elliptical form the heads, 56, of the studs, 41, may be exactl similar.-

Where the springs are relie upon for transmitting the driving effort or absorbing the braking strains, it is desirable to prevent excessive distortion of the flexible connecters longitudinally of the vehicle and to avoid imposing the entire strain of this work upon the annular or triangular portions of the device. In such cases I propose to form the headsV of the attaching studs as shown in Figure 16 for the triangular connecter making both heads concave,-the upper' one, 43, as shown at 47 ,-and to insert a comparatively hard plug, 48, which may be made of rubber rolled rather tightly with a layer of re-enforcing fabric but which should not be of entirely non-yielding material. 'This plug, 48, will tend to transmit the longitudinalstrains which are almost of a shearing nature inthe connecter while at the same time permitting distortion of the connecter about the center of the plug, 48, as the approximate center of angular movement. As a modification of the structure of Figure 16, Figure 17 shows la connecter in which the upper and lower surfaces are both flattened so that if desired the connecter can be applied directly to a fiat surface of the vehicle frame and to the fiat upper surface of the spring leaf without the i the interior of the device is filled with softerv rubber at 63.

In Figure y13 at the forward end of the rear spring Ihave shown still another form I of {iexible connecter which consists of upper and lower annular rubber pads, 70 and? 1,

between which the forward end of the spring is clamped and which are themselves'held to the vehicle frame by a single attaching bolt or stud, 72, passing through the entire assem- -bly and secured if desired, to the special bracket, A?, l01u the frame member. It will be understood ythat with these annularpads there is-no distortion of the device to 'be expected-'transve'rsely of the bolt 72, but that the slight change of angle of the spring leaf is accommodated by vertical distortion ofthe pads themselves While driving and braking strains are transmitted to the spring directly through thestud, 72. A v.

`Experience with flexible shackles of the type embodying this invention has shown that the lateral distortion of the shackle by' which it accommodates itself to the elongation or rather the longitudinal movement ofI A 'one end of the spring which results from iexure ofthe latter also serves to yieldingly resist this'movement and thus-tend to dampen excessive spring vibration and to check re` the T-head form of stud of Figures 8 and 9.-

' I find that the transverse flexibility of the shackle-.in either direction mayv be considerr ably modified by-varying the depth -of the cups or sockets which form a part of the attaching means as shown at'5 in Figure 2, at 10 in Figure 3 and at 52 in Figure 12. With a given consistencyfof rubber and weight of fabric .the shackle material may be properly suited lto use with springsl of various degrees of'ilexibility by modifying the dimensions of `these cups or recesses and particularly where the cups arel not relied upon as fastening members,as in Figure 12. This variation in -design of the cups/requires no other change in the equipment. y

While I have illustrated and. described the inventionentirely as applied to the connection of a vehicle spring and frame it vshould be understood that its lutility is not limited to this field but that wherever it is desirable to connect two members with limited flexibility and avoid the transference of vibration from'` one to the other, a connection of this nature may useful. For example, in mounting an automoble motor in the frame of the vehicle the motor vibration would be Aconsiderably absorbed by theuse of connecters embodying my invention and likewise in attaching the vehlcle body to the frame they would serve a similar'purpose. But as applied to the vehicle spring problem I find that they have definite advantages in providing spring control which involves the yielding resistance to elongation of the spring, yielding resistance to spring flexure which serves for checking rebound and yielding resistance to excessive oscillation Vwhich operates to damp spring vibrationV and bring the parts to rest sooner than where pivotal connections are used.

1. A flexible connecter comprising a body of elastic material and a pair of headed studs i 'having their heads embedded in said material and spaced apart therein, said'studs projecting from the material in opposite directions for securement of the parts to be connected .and constituting the sole means of attachment of the connecter to said parts, said material being reenforced by a substantially nonextensible fabric embedded therein, and engaged with the studs under their'heads.

2. A flexible connecter comprising a body of elastic material, and al pair of headed studs having their heads embedded in said material andfspaced apart therein, said studs projecting from the material in opposite directions for securement of the parts to be connected and constituting the sole means of attachmentof the connecter tosaid parts; said material being reenforced by a substantially non-extensible fabric embedded therein and perforated to engage the studs under 3. In combination with a vehicle frame and a leaf spring, a flexible shackle for connecting them comprising an approximately annular member of elastic material reenforced by I ,substantially inextensible but fiexible material together vwith a pair of fasteners ex-l tending therefrom in opposite directions for attachment to said frame, and spring respectively, and a cushion of elastic material interposed between said fasteners within the annular member.

4. A flexible connecter comprising an approximately annular member ofV fabric reenforced elastic material having a pair of opposite openings and headed studs extending therethrough in opposite directions with their heads within the annular member, with a cushion block of elastic material interposed between the heads of the fasteners.

5. In the combination defined in claim 4, said heads having oppositely lconcave portions facing each other and a plug pocketed in said concave faces between the heads, said plug being less elastic than the cushion maf terial and adapted to transmit transversestrains from one stud -to the other.

'6.- In the combination defined in claim 4, 'said reenforcing fabric extending within the annular member 'in one or more layers approximately parallel to the outlinethereof and the edges of said fabric being sealed by elastic material applied to the lateral facesv annular reenforced member, adding .a ller l0 block of rubber between the heads of said studs and adding rubber to the lateral faces of the annular section; and finally vulcaniz.- ing the assembled rubber elements with the studs assembled therein to form a unitary del5 vice.

THOMAS 1. DUFFY. 

